Synaptic enrichment of microRNAs in adult mouse forebrain is related to structural features of their precursors.
Within mouse forebrain, a subset of microRNAs are significantly enriched in synaptoneurosomes (a synaptic fraction containing pinched-off dendritic spines) and a subset are significantly depleted relative to total forebrain homogenate. Here I show that, as a group, the pre-miR hairpin precursors of synaptically enriched microRNAs exhibit significantly different structural features than those that are non-enriched or depleted. Precursors of synaptically enriched microRNAs tend to have a) shorter uninterrupted double-stranded stem segments, and b) more symmetrical bulges containing a single nucleotide on each side. These structural differences may provide a basis for the differential binding of proteins that mediate dendritic transport of pre-miRs, or that prevent pre-miRs from being prematurely processed into mature miRNAs during the transport process.


METHODS
This article was reviewed by I. King Jordan and Jerzy Jurka.
Smalheiser
Neil R
NR
Department of Psychiatry and Psychiatric Institute, MC912, University of Illinois at Chicago, 1601 W, Taylor Street, Chicago, IL 60612, USA. neils@uic.edu
D000818:Animals; D001483:Base Sequence; D051379:Mice; D035683:MicroRNAs / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016548:Prosencephalon / Q000378:metabolism*; D012322:RNA Precursors / Q000737:chemistry* / Q000235:genetics; D013574:Synaptosomes / Q000378:metabolism*
D035683:MicroRNAs; D012322:RNA Precursors